Commit Graph

126 Commits

Author SHA1 Message Date
Mehdi Amini 1380edf4ef Revert "[ThinLTO] Add an auto-hide feature"
This reverts commit r293970.

After more discussion, this belongs to the linker side and
there is no added value to do it at this level.

llvm-svn: 293993
2017-02-03 07:41:43 +00:00
Mehdi Amini b0a8ff71e5 [ThinLTO] Add an auto-hide feature
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

This is a recommit of r293912 after fixing build failures,
and a recommit of r293918 after fixing LLD tests.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293970
2017-02-03 00:32:38 +00:00
Peter Collingbourne d22ec64b8a ELF: Simplify naming of object files created with save-temps.
Now we never append a number to the file name for task ID 0.

This is similar to r293132 in the gold plugin.

llvm-svn: 293138
2017-01-26 02:18:28 +00:00
Peter Collingbourne 628ec9f193 ELF: Place relro sections after non-relro sections in r/w segment.
This is in preparation for my next change, which will introduce a relro
nobits section. That requires that relro sections appear at the end of the
progbits part of the r/w segment so that the relro nobits section can appear
contiguously.

Because of the amount of churn required in the test suite, I'm making this
change separately.

llvm-svn: 291523
2017-01-10 01:21:30 +00:00
Davide Italiano 19d647b667 [LTO] Catch up with llvm. Modules without DL are now considered invalid.
llvm-svn: 289722
2016-12-14 21:58:26 +00:00
Sanjoy Das fd4016b7c7 Fix TBAA metadata
The existing tbaa metadata in the test is ill-formed, and fails the
verifier after r289402.

llvm-svn: 289405
2016-12-11 21:10:11 +00:00
Ed Maste 8fd0196c6f lld: Default image base address to 0x200000 on x86-64
Align to the large page size (known as a superpage or huge page).
FreeBSD automatically promotes large, superpage-aligned allocations.

Differential Revision:	https://reviews.llvm.org/D27042

llvm-svn: 287782
2016-11-23 17:44:02 +00:00
Davide Italiano f4de3b68bb [LTO] Remove a check on datalayout.
Now that lld switched to lib/LTO, which always calls setDataLayout(),
we don't need this check anymore.
Thanks to Peter for pointing out!

llvm-svn: 287699
2016-11-22 20:37:37 +00:00
Rui Ueyama e8785ba4d7 Change the way how we print out line numbers.
LLD's error messages contain line numbers, function names or section names.
Currently they are formatter as follows.

  foo.c (32): symbol 'foo' not found
  foo.c (function bar): symbol 'foo' not found
  foo.c (.text+0x1234): symbol 'foo' not found

This patch changes them so that they are consistent with Clang's output.

  foo.c:32: symbol 'foo' not found
  foo.c:(function bar): symbol 'foo' not found
  foo.c:(.text+0x1234): symbol 'foo' not found

Differential Revision: https://reviews.llvm.org/D26901

llvm-svn: 287537
2016-11-21 13:49:57 +00:00
Davide Italiano ccf2fa1cb6 [ELF] Clarify why `lld -flavor gnu` is used.
Pointed out by Rafael!

llvm-svn: 286857
2016-11-14 18:20:20 +00:00
Davide Italiano 604d313816 [LTO] Call llvm_shutdown on early exit.
In a non-LTO build is a nop. In a LTO build, we deallocate/destroy
managed static and this allows us to get the output of, e.g.,
-time-passes without performing a full shutdown.

Differential Revision:  https://reviews.llvm.org/D26517

llvm-svn: 286493
2016-11-10 19:39:05 +00:00
Eugene Leviant 825e538559 [ELF] Better error reporting for duplicate symbol
Differential revision: https://reviews.llvm.org/D26397

llvm-svn: 286244
2016-11-08 16:26:32 +00:00
Rui Ueyama 5fc84a1828 Remove string table offsets from tests.
<N> where "foo (<N>)" is the offset of string "foo" in the string table.

llvm-svn: 285751
2016-11-01 21:26:28 +00:00
Eugene Leviant b380b24e6e [ELF] Better error reporting for undefined symbols
This patch make lld show following details for undefined symbol errors:
- file (line)
- file (function name)
- file (section name + offset)

Differential revision: https://reviews.llvm.org/D25826

llvm-svn: 285186
2016-10-26 11:07:09 +00:00
Davide Italiano 726f96e63f [ThinLTO] Test we handle collisions correctly in presence of --whole-archive.
llvm-svn: 284050
2016-10-12 20:52:52 +00:00
Davide Italiano bcdd6c60a0 [ThinLTO] Avoid archive member collisions.
This fixes PR30665.

Differential Revision:  https://reviews.llvm.org/D25495

llvm-svn: 284034
2016-10-12 19:35:54 +00:00
Davide Italiano b67948f497 [ThinLTO/tests] Check we don't fail if --thinlto-jobs is not passed.
While here, fix the CHECK lines of an existing test.

llvm-svn: 283889
2016-10-11 15:32:34 +00:00
Davide Italiano 4683f9d7dc [ThinLTO] Attempt to fix the test (and the bots).
llvm-svn: 283826
2016-10-10 23:56:13 +00:00
Davide Italiano b6e6e4a074 [LTO] Split the options for ThinLTO jobs and Regular LTO partitions
Differential Revision:   https://reviews.llvm.org/D25452

llvm-svn: 283817
2016-10-10 23:12:14 +00:00
Davide Italiano 7a7b35ae3b [LTO/Thin] Make the number of threads to run in the BE configurable.
Before the default was whatever number hardware_concurrency() returned.
Users can specify the number of threads via --lto-jobs=X option.

llvm-svn: 283787
2016-10-10 18:12:53 +00:00
Rui Ueyama 062d7e4911 Removed a test that should've been removed with r282916.
llvm-svn: 282926
2016-09-30 20:17:26 +00:00
Rui Ueyama 3d0f77b281 Improve error check for an empty archive.
Previously, it warned on any archive file that has no symbol.
It turned out that that is too noisy.

With this patch, it warns on such archive file that contains no file.

Differential Revision: https://reviews.llvm.org/D25111

llvm-svn: 282885
2016-09-30 17:56:20 +00:00
Davide Italiano 786d8e33db [ELF/LTO] Switch to the new resolution-based API.
Differential Revision:  https://reviews.llvm.org/D24492

llvm-svn: 282656
2016-09-29 00:40:08 +00:00
Davide Italiano c79d196c8e [LTO] Add a test for invalid alias analysis pipelines.
I found out this wasn't tested when looking at Vedant's coverage bot
numbers, so, thanks to him. While I'm here, switch the error message
to be lld-compliant (first letter lowercase).

llvm-svn: 282335
2016-09-24 20:05:52 +00:00
Davide Italiano 1c3c3953c6 [GC] Don't crash when printing the special Discarded GC section.
InputSection<ELFT>::Discarded has no name and it's not backed by
a file. Trying to report it as discared will cause a nullptr
dereference, therefore a crash. Skip it.

Differential Revision:   https://reviews.llvm.org/D24731

llvm-svn: 281946
2016-09-19 23:15:51 +00:00
Rafael Espindola 8db87291ef Internalize common variables.
Before this lld was always creating common symbols itself. It worked,
but prevented them from being internalized when possible.

Now it preserves common symbols is the bitcode and they are internalized.

Fixes pr30184.

llvm-svn: 280242
2016-08-31 13:42:08 +00:00
Davide Italiano 35af5b3d21 [LTO] Fix the logic for dropping unnamed_addr.
Differential Revision:  https://reviews.llvm.org/D24037

llvm-svn: 280144
2016-08-30 20:15:03 +00:00
Rui Ueyama 94f3a731e5 Convert DOS-style newlines.
llvm-svn: 274118
2016-06-29 10:39:00 +00:00
George Rimar dbbf60e590 [ELF] - Check the input bitcode files for compatibility.
Previously BC files were not checked for the same platform etc,
That lead to confusing error "Invalid section header entry size (e_shentsize) in ELF header" when
mixing files for different architectures.

Patch fixes PR28324.

Differential revision: http://reviews.llvm.org/D21832

llvm-svn: 274113
2016-06-29 09:46:00 +00:00
Davide Italiano 60976ba86d [LTO] Infer ELFKind/EMachine from Bitcode files
So that users are not forced to pass `-m` on the command line
when the inputs are all bitcode.

PR:   28268
Differential Revision:  http://reviews.llvm.org/D21779

llvm-svn: 274107
2016-06-29 06:12:39 +00:00
Davide Italiano 595ee8cb9c [LTO] Include ASM undefs in llvm.compiler_used.
This fixes PR28218. Thanks to Rafael for spotting a failure in
the SHARED_LIBS build!

Differential Revision:  http://reviews.llvm.org/D21577

llvm-svn: 273451
2016-06-22 18:09:23 +00:00
Rafael Espindola 254b58dfe3 Revert "Revert "Add a test showing that lto produces relaxable relocations.""
This reverts commit r273247.

lld should always use the new relocations.

llvm-svn: 273266
2016-06-21 14:47:43 +00:00
James Y Knight fde8f9bd82 Revert "Add a test showing that lto produces relaxable relocations."
This reverts commit r273074.

Reverting this too, after revert in llvm in r273245.

llvm-svn: 273247
2016-06-21 05:54:41 +00:00
George Rimar d3566309eb [ELF] - Recommit r273143("[ELF] - Basic versioned symbols support implemented.")
With fix:
-soname flag was not set in testcase. Hash calculated for base def was different on local
and bot machines because filename fos used for calculating.

Initial commit message:
Patch implements basic support of versioned symbols.
There is no wildcards patterns matching except local: *;
There is no support for hierarchies.
There is no support for symbols overrides (@ vs @@ not handled).

This patch allows programs that using simple scripts to link and run.

Differential revision: http://reviews.llvm.org/D21018

llvm-svn: 273152
2016-06-20 11:55:12 +00:00
George Rimar d03f97211a Revert r273143 "[ELF] - Basic versioned symbols support implemented."
It broke buildbot:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast

llvm-svn: 273146
2016-06-20 10:29:53 +00:00
George Rimar c31fee2212 [ELF] - Basic versioned symbols support implemented.
Patch implements basic support of versioned symbols.
There is no wildcards patterns matching except local: *;
There is no support for hierarchies.
There is no support for symbols overrides (@ vs @@ not handled).

This patch allows programs that using simple scripts to link and run.

Differential revision: http://reviews.llvm.org/D21018

llvm-svn: 273143
2016-06-20 10:16:33 +00:00
Rafael Espindola 1040b4479c Add a test showing that lto produces relaxable relocations.
llvm-svn: 273074
2016-06-18 00:36:39 +00:00
Rafael Espindola 7ce1bc71f4 Document an interesting LTO case.
This is a reduction from the only symbol in a build of clang that the
gold plugin internalizes but lld does not.

llvm-svn: 272845
2016-06-15 21:33:11 +00:00
Rafael Espindola cc70da39ff Internalize symbols in comdats.
We were dropping the CanOmitFromDynSym bit when creating undefined
symbols because of comdat.

llvm-svn: 272812
2016-06-15 17:56:10 +00:00
Peter Collingbourne a8bf23d656 ELF: Add a test showing that the new local_unnamed_addr attribute can permit internalization.
Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20259

llvm-svn: 272711
2016-06-14 21:02:15 +00:00
Davide Italiano cd76e49888 Attempt to fix non-determinism in test.
Otherwise it could just use a leftover a.out from
some other test.

llvm-svn: 271820
2016-06-05 01:04:59 +00:00
Davide Italiano df24d5b8c8 [LTO] Add --lto-aa-pipeline.
Differential Revision:  http://reviews.llvm.org/D20888

llvm-svn: 271605
2016-06-02 22:58:11 +00:00
Davide Italiano 64ebf32ef3 [LTO] Fix (incorrect) TLS attribute mismatch.
When we undefine, we also preserve type of symbol so that we get
it right in the combined LTO object.

Differential Revision:  http://reviews.llvm.org/D20851

llvm-svn: 271403
2016-06-01 16:38:13 +00:00
Peter Collingbourne 5079f3b727 Update LLD for D20550.
Differential Revision: http://reviews.llvm.org/D20704

llvm-svn: 270968
2016-05-27 05:21:45 +00:00
Davide Italiano d26c4a14ca [LTO] Add the ability to specify a subset of passes to run.
Differential Revision:  http://reviews.llvm.org/D20267

llvm-svn: 269605
2016-05-15 19:29:38 +00:00
Davide Italiano 334fce92d9 [LTO] Don't crash on old DebugInfo.
Drop them and produce a graceful warning instead.

llvm-svn: 269149
2016-05-11 01:07:22 +00:00
Peter Collingbourne 3ad1c1e242 ELF: Undefine all symbols, not just those that we expect to be defined.
This allows the combined LTO object to provide a definition with the same
name as a symbol that was internalized without causing a duplicate symbol
error. This normally happens during parallel codegen which externalizes
originally-internal symbols, for example.

In order to make this work, I needed to relax the undefined symbol error to
only report an error for symbols that are used in regular objects.

Differential Revision: http://reviews.llvm.org/D19954

llvm-svn: 268649
2016-05-05 17:13:49 +00:00
Rui Ueyama 6d0cd2b62b Teach Undefined symbols from which file they are created from.
This patch increases the size of Undefined by the size of a pointer,
but it wouldn't actually increase the size of memory that LLD uses
because we are not allocating the exact size but the size of the
largest SymbolBody.

llvm-svn: 268310
2016-05-02 21:30:42 +00:00
Peter Collingbourne 4f9527065c ELF: New symbol table design.
This patch implements a new design for the symbol table that stores
SymbolBodies within a memory region of the Symbol object. Symbols are mutated
by constructing SymbolBodies in place over existing SymbolBodies, rather
than by mutating pointers. As mentioned in the initial proposal [1], this
memory layout helps reduce the cache miss rate by improving memory locality.

Performance numbers:

           old(s) new(s)
Without debug info:
chrome      7.178  6.432 (-11.5%)
LLVMgold.so 0.505  0.502 (-0.5%)
clang       0.954  0.827 (-15.4%)
llvm-as     0.052  0.045 (-15.5%)
With debug info:
scylla      5.695  5.613 (-1.5%)
clang      14.396 14.143 (-1.8%)

Performance counter results show that the fewer required indirections is
indeed the cause of the improved performance. For example, when linking
chrome, stalled cycles decreases from 14,556,444,002 to 12,959,238,310, and
instructions per cycle increases from 0.78 to 0.83. We are also executing
many fewer instructions (15,516,401,933 down to 15,002,434,310), probably
because we spend less time allocating SymbolBodies.

The new mechanism by which symbols are added to the symbol table is by calling
add* functions on the SymbolTable.

In this patch, I handle local symbols by storing them inside "unparented"
SymbolBodies. This is suboptimal, but if we do want to try to avoid allocating
these SymbolBodies, we can probably do that separately.

I also removed a few members from the SymbolBody class that were only being
used to pass information from the input file to the symbol table.

This patch implements the new design for the ELF linker only. I intend to
prepare a similar patch for the COFF linker.

[1] http://lists.llvm.org/pipermail/llvm-dev/2016-April/098832.html

Differential Revision: http://reviews.llvm.org/D19752

llvm-svn: 268178
2016-05-01 04:55:03 +00:00
Rafael Espindola cceacd7113 Don't depend on lld creating relocations in ro segments.
We currently don't do a good job of diagnosing inputs that would require
dynamic relocations to be applied to read only segments.

I am about to improve lld in that area, but unfortunately we developed
tests that depend on the current behavior.

To make clear what is actually changing, this first patch just updates
tests to not depend on the current behavior. In most cases this just
means using a rw section instead of a ro one, but that unfortunately
changes many addresses.

llvm-svn: 268145
2016-04-30 00:49:10 +00:00